SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8ba24091274724f6621f6334b62cff08e8d3024911e4773dc01e692e7825f25' 
  AND token = 'apwzIW306WSYssMP1/MzUZ57UXEos2OSy+QJiil9h5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}