SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d95a620db76cb25cadf1837df2ee5a64d1397b88b853b5d8a9736a5642b57cd' 
  AND token = 'wzOa/IBfAfYGn90QCxnBtkndFZ9ClWxhP0EV3YuJIlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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