SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ed0e0d1839e38f3103f55f76fe8551e7bca13817762816921af96be2a8e2cc' 
  AND token = 'aTchHhj4uJdWbVKh5llPNsHBVkaUNfXGJFFkdRoMxuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

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