SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e85846840a97d956304c4fd7d4179941582156796b60ec062d8f511e32b9d051' 
  AND token = 'AWh9GQK9/Y8yZnK4lZPU+S+UHeuzF0vj1fdawvelw+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}