SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30396d45e382cc2dad1358f4ba6875befda4138a67bef4e8f315511577e0d100' 
  AND token = 'IW5+hMcKJXp5thun7MnChKdEO7KXAAGeNYlnJ1cqebM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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