SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2360e1cf5fb1ddcdd6125acb0c6833f3552f822ab05f94619b49da8c259759dc' 
  AND token = 'rBT16v9XKiLFt+Twlk/7v3RCQhTE5U/OGCUItfxbBV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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