SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea656f3e30fa441a30d83e4f300aeb3da4672d1de5844fcb9546ff42230c8d84' 
  AND token = '9Wquj2WCdndaPYjsKlbqn5rtPzk4cGV0XEiYNa1uxnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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