SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c85b15d10ca5dfa670a6061f9fa603c150e839e6e236e1bbf2d26e0ffd27c355' 
  AND token = 'HCI82nOb3wOrwi2hwIZl9H9XKUOCewDiXOek5FT5uBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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