SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4bca294637111402dffb6b2b87aa674a91394032e0a94aba4242cb383752ad2' 
  AND token = 'GbxpdKwyCHny48xhYbOkXYd0MS0xpVAp5ziPq+lLb18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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