SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d6c39260bd58b5daab1c81e355e7a24240fde2a154c1dc7ff457419b9d02b4' 
  AND token = 'RsdtT7y7c11p7hGrI+UKo/lnDcq4QWxPyUBzpCD7we0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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