SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00830d0c1a1fb27c40616956003b7c02bbbfa04fcfb78452fff321fcb60633b1' 
  AND token = 'k1RSEoBdiMMkeJ7zOC8Fb5G5vQ0fnqVgfci6ccoLjqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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