SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625424d82a2d9649487378b60b3c4d5a5d228fd1c3fafec1ca61aef9f8fc202c' 
  AND token = 'As3+iBAy2S1HLZvqWeOQVshDUX/e1NYOxwqurCAZ6Q8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}