SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e92b995831da1343fe165a06e671415338190253d265ca348f8fdf668df32a55' 
  AND token = 'zta+VHCoTlXOea6GQ+DYDzd4P0MsWCeU8b3EXX5Z6s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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