SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d5153a0a393b6dcd8cc83b4f97ec674ef5ae5fa113843d671c7b6b437d9d483' 
  AND token = 'w6PoHKvkKJW8O9Oazr/XRGznPU8pbjcFBjHtRHcKEdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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