SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad3780368f34accafe3e63846634f05a7e372a67d7740f151077ad577bb21c3' 
  AND token = 'i25eMMdmwbFcHuxDjit8/H0i9qn3NxVogFH8WBxbLGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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