SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f1b1363b69e90ea8aa6b2eeba6b5ef564a98bec4d4d2cebc8072b99fd11629' 
  AND token = 'JKPercLHHvxRVkn/zmt4AlvEqAuJIMqljPMAQlKyMaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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