SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '32aa73ff48a72410816cb927bda640c64d6a3eaba57e456da3fa38ae158af631' 
  AND token = '1xdyf/4scbYDljRo18HOVhMpl3x+ocJaClyovoGCcn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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