SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '600a519efc02237a903dcc79182697d2982015ea29d2ee105e8698151951824b' 
  AND token = 'nTqbCZDNjOdr1fRj/8iabz9St1isUTW6kzb+viv8vBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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