SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3b4fa0b2448292d7b07ad55eaebac3d1affa6538fdf10b2a00d1af5fc3191e8' 
  AND token = 'vxtvoYBQc/hz7KztSWCPnxDoIDaGwVW7eGIaPA9HFF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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