SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df813baca74d867db75a4f20705febb3f3732fb6985e4e3b9db51bf344cd1ef5' 
  AND token = 'mxUJaOQTF9s80Aj+I6M8w20PQmpQhxl2iLkxKjzYTZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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