SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd906416d02363e14cc8610d2894cefe43a3b53cf608e17036bb8ca9893c232f3' 
  AND token = 'WouyGYr/GN9/CJJZoCmdoBvZTOEx0hDgmsp3NZcGnqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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