SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee0ac83db114c9f79b834d89c9beaeadc3bc5054c1e20b3755463f326ac2a4e2' 
  AND token = 'aeMQmw1uNhmU+JcVmEgOufQ3JzYqoBHv/e8PzsLo4Qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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