SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66b13dd4d34e3c2dc72ebffd253e69b1547e5a71b6066744e8a1206069be0cf5' 
  AND token = 't9KOFYHomkIio3GwU9sKItPB17vzEjhSzzbFI+WQwc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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