SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20030acd6c480de2f1d0e019fcd1be94bf4de1b57254aaca9b0022684b0af04a' 
  AND token = 'vQTGLgjDvvIw2zA6/RMUwmzwLpQoqQuIbJXSLmdiPGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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