SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2363fba19cb77c009eeb312e45ec927e8b91ff8b72255d3a0dd3e72851d62ab3' 
  AND token = '08bCaQUWTk6bKUHtItXh/+BXbz8sEJeDI85oXrDwsBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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