SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92da11ecfd1fb8546e0e5c8e5fa6d276856fae28624a14b5c4ef588b0d977bce' 
  AND token = 'xceRC+8SVwceXuCFgcs5z+Pn2jXLYVkPGnYmYvlRWFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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