SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed994c74c26322b36141b17088b9d25c3ac5ce489e81f6f6801a2b35e32b1f7d' 
  AND token = '+F9blvViICBLHPTCEWDjTBL/rsGWvEW4YNOWRapApW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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