SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cbb2fc9d7829e9565969fd29a8d4ccdd003252c4d2b39b8952391632c163d48' 
  AND token = 'AsJ6VoRSen9dIfKJboXy4aApJbra01NvULwNEIkJblc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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