SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7484e74d3fa92eb0c7c33a1493d8478876a75df40d6d372f62684808d2db9116' 
  AND token = 'hYXRilqbKBX0h8QSjOHgOPhKAdFamjTZptbcJS7uABI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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