SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27495b3d00496d1da129fdc7710e3b51c917b6a506764fbbf08aceaae9082fbd' 
  AND token = 'LdPw5jLn4xmzKOOK7La66nEqOSomIESfuVX8qLCnCVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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