SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f47578b351a975e7e8ceba133e24a37050201d2f135a8898ca05de88d3525c8' 
  AND token = 'v6c995kqcc0Tqua8m1G7onjil7hGNLpQ15w1te0JRD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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