SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06fb1a4ab9dd1c558bad3640dd979b470a4149a75b5a0362134d4c8364f3e747' 
  AND token = 'XSv2HcQ1G3KJRQKSgKO7/Y8TgvCPvjeqBS9YrZ1pI0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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