SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23586cf95885539575cf30d935a370946c21f20bd75e9ea5d38567362ca1d232' 
  AND token = 'PSV/gYd0381F9OrBqVDb2hA8a2qtnRnRZhAUi/zB6EA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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