SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7fb02053d8184098109f03834e971f6ebdb23c7a4ef3e34b5a6ffc3cd9a7192' 
  AND token = 'zHIX8vzLZu17ZNJ4DhPLGHhpeTFbitQg9zi/yaXCUHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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