SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7717ce30b3ed3ce4507975debdd932f6caac659fb2b81fa6e005f60ea07ff28' 
  AND token = 'AjHEcBZgYalaeSK/7nBeyu1Aj61lWGz7G+dF/UbsnI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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