SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abd49b9c5b301ceb092dd8252cf04c7ace2061c7cf73486dd50ce5477f0e46a3' 
  AND token = 'W0Uh7ub4NUmNPOeUQuyqXp8XgplpJMQmxhDKER8gvOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}