SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78eae427cec284fb3b3b9791020845f7b75fd1260a604db8db22b79cd270eafe' 
  AND token = 'lW2LjyfiBgkLb+hX54tgC5RnH2xHU9A72+9hPyvZwIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}