SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e58cdc31510471c2982fe81375a470bd20078b75f42f236ea996d00c61362d19' 
  AND token = 'jecTPaoc2YuC7jIV+WyWxVwqXER9veZqFydSnXWSPKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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