SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ce8d7a5b1cdf0c26ff1db034791a80ca3d6c356fbdbb4fd66ef9305d09febf9' 
  AND token = '9UAeHjcpBapBz2tNb6jFLKVUzxVWPYp+exu1JQaaphI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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