SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ea7c2026a51a085e69dd1f6fa4e8779f88390b35eff59e268b01e3995a56ea' 
  AND token = 'ZkQ1oMz2DXKF1SrSKmhQRFFqum7Dxo+dJJVRqHpLYGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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