SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde972fad73596ec10a66be905ec742e50b3425592315cf25585d66e83dd0a1c' 
  AND token = '/gSsKUGfxCIR6fkPm3KcZT7KqhQXmSY8jsfKQN0lugw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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