SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7c9ab300c6dde94140b725f81f3447556a419d9d5c95b8a030bfd033e1c9f26' 
  AND token = 'IwD9kmdF1mPLlzloVxkPlTDc1rCVBH4KQpmyi0R9ymc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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