SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40989d1aa32d10edced5cf01f9fd40cbc9679e05d046d154249a450576b46afe' 
  AND token = '+nYlGKP5Sf3WzaWDk8lZwzZmZpNd8ch9vyeqvEeEAuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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