SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b0e76419567a0faafed0a3c86d25848c5bbf61c80d49041d55c8be2e38d6803' 
  AND token = 'H2br5rar8KZfh2D7gyzqTWnFMNo/4UA2lHo1R3I9rcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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