SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84f7c763975ecd42abe46ce89b5db365fb4935a4a097b5980837b86f3298301c' 
  AND token = 'lKFTqUTkKHF0DxwHh4VM2jt3Qkf/9lXAwPm+YQ/gZkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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