SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9df8a284c0f64bc8f9c816b083211b4f7c37e7a389ea41ea2347ac4fd758a267' 
  AND token = 'b3Kg5dRORNoLSFoBVTYr+yLLtzHCGTyEOlmwgk+bmWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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