SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6da8e8f9b28fec86507227fa94dde65aa51cb77a913d6babe10657434c7052ee' 
  AND token = 'lAUILPYIC7Bfjmw86QcM03oCkyCN0s+EI0/8KTsObCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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