SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a25a196b953f4f46a5b4bf3f0be4af5432a708a28481a32c9e87408ff74a1659' 
  AND token = '0JvGIFhGsUoYeY/PDNG+cg2/H0hE0cL2Vd8BEVwq30M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}