SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a67719b636f3ed60d4eb90afc10510be20a10352112697f8acfaffef2ee4093' 
  AND token = 'cWvgbNqIKRy3Vn3yON0ToMcs/fDX5AkvpciOzPFxrbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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