SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91ba884e58e9bab001ff84152f55619b38de8cd7e21d2e38b92ec82e0cc0e617' 
  AND token = 'nKWBvlLKVaqGutjCKxlvtDydYGtxzHLDGJ/Z+xR0EGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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