SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27523bac8fd1f3d7e4ec15009d1095152758085c97958682a41f4642e6b96fef' 
  AND token = 'QuB4zk2A+PtIFIG8MIRPnLetm2HgRfejXVps/G6bX7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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