SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e98a48eabd71b23e92d8bbddccdc4aeb68291e01e6d9262e5e613abcc303f9bc' 
  AND token = 'bmgML1dOa8ofubFA2XLHRr47V80jP/peYrQGPuEgyf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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