SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a35ae3b276bbcc8ac35f887c891465f4d945e0f5d31dafdfad34de1cce7108' 
  AND token = 'Q6h6F5yk9uylNtsTZjdyHDbYZ82rXYK6fGHxluVEchY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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