SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8450864770275737df9dd21ddc78d6f91c3b48e49d76b2bb023d0c1d50c4fdeb' 
  AND token = 'xAXY9JqJikY6/rUttX+2tC1LZKZrMH+DAITjmjLKGys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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