SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07774def8a8670fb46495a294668e214ed85b923a58da9b67750943805da3705' 
  AND token = 'UH+s8ROv3h45XdALQiN6bn8urpFe9bL32wT3Su84fBM=' 
  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"
    }
  }
}