SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b25346c0664e9c8bf33b815b4c39aa1dee7d433a610019847a34bc998effed4' 
  AND token = 'PTdPeER7j7v7EqJppdS2G83yaeDLggSfDRZRqoJHIDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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