SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b1341b91c647ba5abf627a8b583bcdcba8250cd013980a32f9ad490f05856f9' 
  AND token = 'A0e8PVeN5R+PB6igyQzJvh2YvKFmM/hDwUtWD22HQdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}