SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7afa6c388c73a59a751a37f4385d39a65c78a128c9c0d629c20b77762ccc990e' 
  AND token = 'RgU+UyrNYoKmktQAjjiG4xGHGigRJxolgR4XV9qn1As=' 
  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"
    }
  }
}