SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6503982d668f9eb10d1f874f0f611a4b52ccdf63eb6a81b6e15cba57777f28' 
  AND token = 'dWJe5Ck6KNkEEJwa4AMPSY8uAZe44fHCoWI/2/lJxUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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