SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '53ec056027ca37b0248344889f81a145ada8eab66392c0183f735e047ffa33a5' 
  AND token = 'qMSerOWH4Kx96KH3+jvBmIYt8PAGY8b8mCvr2vjuCso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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