SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '606e7ea6260615bdf55e50f878d61173094679640ce7c798c75de7666bd6d8a9' 
  AND token = 'K1teSweoWAEUPY0cDTMShm/hLQnzhMmvqlC1mvW+Txo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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