SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0881a78f2bce2609d0b5f023cef2e4eb058deb4e311764f530b24faf449c7ff9' 
  AND token = 'I/v43AY6PHCqE4/76ORN8WzGQJTF/qs6QvBsK3VwI0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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