SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c29e1115392f1dcaf3a3f6c19fb0bc20bc86e950a2f66670e86e5d62feb2e158' 
  AND token = 'i+uosJnh+Uva8h3EJiDEfYSbAPYFcDJBVxcCu6kemew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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