SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '958292ceca535f49713645efd897593ddb4adb91298edf9c5dfa6192ac950f81' 
  AND token = 'Q7f0g73/QqnISIsjMEgtWTBTTBQm8gTFd/0soEwKYJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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