SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55e97baab5afeb8b7bb7f66426973a303c4b97411a449b1950bba99c3831e795' 
  AND token = '4A0z6NQ2QVdGXcSfqnuF4cq5qStzr1ESCA7oLM7OKeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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