SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74d5287f23aa2ed0811f54ed51d446ec47ea01d94d0b74f14be066cefa1f9611' 
  AND token = 'fmYNoEvTKtkFhPrzALWdZlMzvtO+GNqj+gkBg4MTHAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00104

JSON explain

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