SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f436ef343179d8e6deaf0370df0365ec99e0536c17c793d2387fb77b13e52b5e' 
  AND token = 'AwqftFdOVAPayHQ7qIw56UQeXDIQZZoboCqgsOj9x1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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