SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9c8f3ee4e36c8d99a0b8c51daf6e87a11584f0f5d3899292200fac735349115' 
  AND token = 'AXIAogPE6FBruq9RiJvIn7NJpBXgus1Gn+rblMXvyZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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