SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '901442df7e296bfc4b5870e344e2f987d3b9500afc10f6fc4cecfbb745cf086c' 
  AND token = 'zTrvnsXQWHxfsw7uxuvz4PbRZn8O3vp+QWCSatq5khM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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