SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f22b209663db6b97e9e7a1a935a82af39714edbcd9cb69781fefdbde4ad7581' 
  AND token = '1rSWYxQ+1HEWiI8yayNizUSjRWApmggZ/LhLgdPFVNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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