SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01db777b7ae314f4b2afbcce2d9e6d6963fa6fe57101dbfd88a2191e8871ee27' 
  AND token = 'yyY8FYwPcDPILbMvuda8bTd1mCLYywEz323Fjp8d3Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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