SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10a56f60807c055a85cb64716e8b7350f8d3be3a8c13bc547a2fbc6435507a9e' 
  AND token = 'v3LdEKJu2tzPRwOgcJF2iMkNucgDk/XjLnHAFCexsRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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