SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b9fc6c4665e4c6b5cce9a30c50fda858fe8d8eb6d59ebbbe3ead916948de3e1' 
  AND token = 'J+pLusnLwQ+6BJWrvcubw+L2vzQvM4W+6EYf5ndin+o=' 
  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"
    }
  }
}