SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9762e4fc58edc876d43349ae8813d1e175ddfe598240daaed8725290fe068d7' 
  AND token = 'd5LeAWvhvQvb3IVqJxSYTQysNRfjOntBY+opQ08jG9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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