SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f79edfa4d6ef04828b1de45243576f1e2fd8e22cc01777bd5ad6d807658e3dc' 
  AND token = 'NmuG6yyvCRAFzszjQzEGUzSYaR7bb0d9SetU5Pt1aB4=' 
  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"
    }
  }
}