SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2173cb6fb5e549b31ac3b9a6d8dfd553025c97a80ac345b34d5c5874f48bee92' 
  AND token = 'tfpuFoILcXiniJRfRE51TxL0/Vy2kXVYqLVQUYdhUyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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