SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bfb8074cec4b6f063eeaa1c32e87c7a02e09db77c5cafa0c3c7a67aad53190f' 
  AND token = '4pqJsGYmAhPKvQzvjSGHrS2F3HVUZz3T2xVBwuoa/BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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