SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '286c458c78c90bb09650209996d89646afa17999a4873a17d24a4542bc418ef9' 
  AND token = 'qEXB+/R2TPpo6YV5Spo0qOsKqccyT+dXfuozXwzlVkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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