SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f89aad92db0fb1b1c55f349560dbd815edf9ca5e9ce6f15450b5606a6edf1f' 
  AND token = 'S5brWcF2DB88cL7ZBzfgE+OIRdTxvr4fcxk09mEaRrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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