SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd29f20677d0769c25a08af2b19debe717eeeda7d9d7b62b43851180edc089394' 
  AND token = 'ZuyN+kghYzSKFGK8fZ/lZlVsRzFqn4wFMCX75c99JVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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