SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950e9e05c7eb6c9812ffe90f371ae0beb6010aa32d082058639acaa08af0cd52' 
  AND token = 'VvyamACmmqYu110+mCDiiQyWtRy6+GPlJOPRmgVd0us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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