SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cee0dee2395fdd959d78349a2ac3ff05b23b3e958100ecec33f0d30c9343e97f' 
  AND token = 'JzXTvzflD88PDHbeMIBwE+P9EUXBTIYDb3D254MO98o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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