SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a92a62be360fed3d8532a49a956248e87667f7a9df203b8c2e5c72ab679ab25' 
  AND token = 'oP+GTxZCzTbcnHx4S+g5VKK0pRBjODRL9RXVrcz5qdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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