SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87dcc37f1d4ec3e1df91f4e9c360f1cb128ea598cd0e165a74108f4923bbfc91' 
  AND token = 'CIrjRWcR5QWBZzmoKgeplrrTmqMhdgElAYqXH5Yawlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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