SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325f5120a15c920e86ff0c62b1ecd56cf909f96a11dbf5368f81c158418d943b' 
  AND token = '3RjP+PHwAypTUUTnWxAs9ofK96LeBJUsXI8STbdbots=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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