SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc7133d20d127ef4facc6bbc09d82a83e7d94f1a1e20b6427b7a57a335678e79' 
  AND token = 'sDCESmEOSPhaiVASv3rrz97h9rGe6uynZlcEAZCRFvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00007

JSON explain

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