SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19ec3d8d293e6e6cdf995cda753fb92a57e6ce08318251684ca21a0fb0aaf458' 
  AND token = 'PSme2KP8Td77zK+56X7IjHq7W+67NTr7gtF6owv7aF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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