SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa5b4f606c15f872bd41ba1174a2fe5de3a020d04a85869e4b575365ab2aadee' 
  AND token = 'PuEAtSeYULZqUseVOdiaaCR+SPio2i188H+EhZME7ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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