SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddd25cd50943d554825c9eefafb507f1548c704016976603be7daad6f1d5ed43' 
  AND token = 'TsOdZlEa20IASPqOtHXyQxZTapTtHiqGA51VDURaBT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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