SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e0073e48a384786412940a78aad507fe0009ea76e29c48ec60fa593ceddc94b' 
  AND token = 'GSt2rv6+FGJzBIMwU+qnXGwuJXtsZx7tOWB28/AhVlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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