SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1dafc10413fe4768208c4ae381de4b18f273060ccf83e2241750d430b0fb41a' 
  AND token = 'zJgR8fA+wscrBnzvGMG6edC0ZdiVxYfy7TgZ56+pFT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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