SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e96c441a4356c119cd4222766080f2240c40f02f15dd008e3691efa72b22e4f3' 
  AND token = 'M4nm+iuz7oJYxAjOWy99rhPS1239toPghRaA5ye1Fyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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