SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc293458f4e32bc382bbb61fafc7b0008ef8f3dc05fbf5f62bd6d9bde59fb8ab' 
  AND token = 'BqxGJG+mXKfPbrfyy8g4jAwAouFdUDKB9OYbtZXfEQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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