SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7468a093d02a9cfdd5956b888d9431f3aabb9cb1185a71e6656132dcbe9abe33' 
  AND token = 'wl77TJ2QDN1SBwtKRUgIqv4zbnNulk5Gl47AtC50WII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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