SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3414b2bc737676ca026d2ad942158a0cf2058b77d0d56704a926288ab13151b2' 
  AND token = 'ZTXLLfIwaKnL9YJ6CU4gw4OynuQy6SMbogBHxQrb6bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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