SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db56b135fb0346233908dfdb2f83f59473d23dea714139cb464b05a7763325a8' 
  AND token = '2sKaWMmDZupLwDcaArHpJSvPVBHlL8zUAJSXZWYOf9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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