SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93b6be2aa9c80307993f19c53948840c62a23ce2b79cd4c6d1f3d4bf14746ec6' 
  AND token = 'lvEA5nh1TYz37NAC/B9Npo3ZmBLvTzkHZeXGY8s+q0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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