SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f99356e34b4faa084c3668475c261983037c70672c47cb827f40b9c342c2f64f' 
  AND token = 'ePcOKQR6XhlfZn6dPlurStVoP1Z6GWXmuTzfvP+lbFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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