SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fcd572d92208919fa16ab16afb1da950b15975e911f10e8b29129c74a846005' 
  AND token = 'RtAFd0tvS/Zu96UNR1cxkOIyFprk5932gfUTmNSeugo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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