SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4767ad9a177a259a6c7895ed32a90da7579d2bba951bc0302888130fd1a61e79' 
  AND token = 'yRF1s3GVc4Y8mClApGZacXD9u3vgk1hxPKd7omagSNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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